Plant-derived flavonoids are a potential source of drugs for the treatment of liver fibrosis.

Liver fibrosis is a dynamic pathological process that can be triggered by any chronic liver injury. If left unaddressed, it will inevitably progress to the severe outcomes of liver cirrhosis or even hepatocellular carcinoma. In the past few years, the prevalence and fatality of hepatic fibrosis have been steadily rising on a global scale. As a result of its intricate pathogenesis, the quest for pharmacological interventions targeting liver fibrosis has remained a formidable challenge. Currently, no pharmaceuticals are exhibiting substantial clinical efficacy in the management of hepatic fibrosis. Hence, it is of utmost importance to expedite the development of novel therapeutics for the treatment of this condition. Various research studies have revealed the ability of different natural flavonoid compounds to alleviate or reverse hepatic fibrosis through a range of mechanisms, which are related to the regulation of liver inflammation, oxidative stress, synthesis and secretion of fibrosis-related factors, hepatic stellate cells activation, and proliferation, and extracellular matrix synthesis and degradation by these compounds. This review summarizes the progress of research on different sources of natural flavonoids with inhibitory effects on liver fibrosis over the last decades. The anti-fibrotic effects of natural flavonoids have been increasingly studied, making them a potential source of drugs for the treatment of liver fibrosis due to their good efficacy and biosafety.

Higher-order Granger reservoir computing: simultaneously achieving scalable complex structures inference and accurate dynamics prediction.

Recently, machine learning methods, including reservoir computing (RC), have been tremendously successful in predicting complex dynamics in many fields. However, a present challenge lies in pushing for the limit of prediction accuracy while maintaining the low complexity of the model. Here, we design a data-driven, model-free framework named higher-order Granger reservoir computing (HoGRC), which owns two major missions: The first is to infer the higher-order structures incorporating the idea of Granger causality with the RC, and, simultaneously, the second is to realize multi-step prediction by feeding the time series and the inferred higher-order information into HoGRC. We demonstrate the efficacy and robustness of the HoGRC using several representative systems, including the classical chaotic systems, the network dynamical systems, and the UK power grid system. In the era of machine learning and complex systems, we anticipate a broad application of the HoGRC framework in structure inference and dynamics prediction.

Unveiling the Growth Mechanism of Ordered-Phase within Multimetallic Nanoplates.

Tuning the crystal phase of alloy nanocrystals (NCs) offers an alternative way to improve their electrocatalytic performance, but, how heterometals diffuse and form ordered-phase remains unclear. Herein, for the first time, the mechanism for forming tetrametallic ordered-phase nanoplates (NPLs) is unraveled. The observations reveal that the intermetallic ordered-phase nucleates through crystallinity alteration of the seeds and then propagates by reentrant grooves. Notably, the reentrant grooves act as intermediate NCs for ordered-phase, eventually forming intermetallic PdCuIrCo NPLs. These NPLs substantially outperform for oxygen evolution reaction (221 mV at 10 mA cm-2) and hydrogen evolution reaction (19 mV at 10 mA cm-2) compared to commercial Ir/C and Pd/C catalysts in acidic media. For OER at 1.53 V versus RHE, the PdCuIrCo/C exhibits an enhanced mass activity of 9.8 A mg-1 Pd+Ir (about ten times higher) than Ir/C. For HER at -0. 2 V versus RHE, PdCuIrCo/C shows a remarkable mass activity of 1.06 A mg-1 Pd+Ir, which is three-fold relative to Pd/C. These improvements can be ascribed to the intermetallic ordered-structure with high-valence Ir sites and tensile-strain. This approach enabled the realization of a previously unobserved mechanism for ordered-phase NCs. Therefore, this strategy of making ordered-phase NPLs can be used in diverse heterogeneous catalysis.

Cyanuric Acid-Functionalized Perovskite Nanocrystals toward Low Interface Impedance, High Environmental Stability, and Superior Electrochemiluminescence.

Perovskite nanocrystals (PNs) have received much attention as luminescence materials in the field of electrochemiluminescence (ECL). However, as one key factor for determining the optoelectronic properties of the surface state of PNs, the surface passivation layer of PNs has enormous difficulty in simultaneously meeting the requirements of high ECL efficiency, conductivity, and stability. Herein, an effective surface modification strategy with cyanuric acid (CA) is used to solve such issue. As confirmed, the CA molecules are chemically anchored onto the surface of PNs via the Lewis interaction between π electrons of the triazine ring and the empty orbit of Pb2+. Benefiting from the above interaction, the electrochemical impedance of PNs is decreased greatly without the loss of light-emitting efficiency. Moreover, the stability of PNs under O2 exposure is improved by almost sixfold. These improvements are confirmed to be beneficial for enhancing the ECL behaviors of PNs under electrochemical operation. Upon cathode ECL driving conditions in aqueous media, the ECL intensity and efficiency of PNs are increased to 200 and 170%, respectively. This work provides a new modification strategy to holistically improve the ECL performance of PNs, which is instructive to exploring robust perovskite nanomaterials for electrochemical applications.

Solvent-Free Ultrafast Construction of Se-Deficient Heterojunctions of Bimetallic Selenides toward Flexible Sodium-Ion Full Batteries.

Flexible quasi-solid-state sodium ion batteries featuring their low-cost, high safety and excellent mechanical strength have attracted widespread interest in the field of wearable electronic devices. However, the development of such batteries faces great challenges including the construction of interfacial compatible flexible electrode materials and addressing the high safety demands of electrolyte. Here selenium-vacancies regulated bimetallic selenide heterojunctions anchored on waste cotton cloth-derived flexible carbon cloth (FCC) with robust interfacial C-Se-Co/Fe chemical bonds as a flexible anode material (CCFSF) is proposed by ultrafast microwave pyrolysis method. Rich selenium vacancies and CoSe2 /FeSe2-x heterostructures are synchronously formed that can significantly improve ionic and electronic diffusion kinetics. Additionally, a uniform carbon layer coating on the surface of Se-deficient heterostructures endows it with outstanding structural stability. The flexible cathode (PB@FCC) is also fabricated by directly growing Prussian blue nanoparticles on the FCC. Furthermore, an advanced flexible quasi-solid-state Na-ion pouch cell is assembled by coupling CCFSF anode, PB@FCC cathode with P(VDF-HFP)-based gel polymer electrolyte. The full cell not only demonstrates excellent energy storage performance but also robust mechanical flexibility and safety. The present work offers an effective avenue to achieve high safety flexible energy storage device, promoting the development of flexible wearable electronic devices.

Effect of Selective Metallic Defects on Catalytic Performance of Alloy Nanosheets.

Defects in the crystal structure of nanomaterials are important for their diverse applications. As, defects in 2D framework allow surface confinement effects, efficient molecular accessibility, high surface-area to volume-ratio and lead to higher catalytic activity, but it is challenging to expose defects of specific metal on the surface of 2D alloy and find the correlation between defective structure and electrocatalytic properties with atomic precision. Herein, the work paves the way for the controlled synthesis of ultrathin porous Ir-Cu nanosheets (NSs) with selectively iridium (Ir) rich defects to boost their performance for acidic oxygen evolution reaction (OER). X-ray absorption spectroscopy reveals that the oxidized states of Ir in defects of porous NSs significantly impact the electronic structure and decline the energy barrier. As a result, porous Ir-Cu/C NSs deliver improved OER activity with an overpotential of 237 mV for reaching 10 mA cm-2 and exhibit significantly higher mass activity than benchmark Ir/C under acidic conditions. Therefore, the present work highlights the concept of constructing a selective noble metal defect-rich open structure for catalytic applications.

Lignans as multi-targeted natural products in neurodegenerative diseases and depression: Recent perspectives.

As the global population ages, the treatment of neurodegenerative diseases is becoming more and more important. There is an urgent need to discover novel drugs that are effective in treating neurological diseases. In recent years, natural products and their biological activities have gained widespread attention. Lignans are a class of metabolites extensively present in Chinese herbal medicine and possess good pharmacological effects. Latest studies have demonstrated their neuroprotective pharmacological activity in preventing acute/chronic neurodegenerative diseases and depression. In this review, the pharmacological effects of these disorders, the pharmacokinetics, safety, and clinical trials of lignans were summarized according to the scientific literature. These results proved that lignans mainly exert antioxidant and anti-inflammatory activities. Anti-apoptosis, regulation of nervous system functions, and modulation of synaptic signals are also potential effects. Despite the substantial evidence of the neuroprotective potential of lignans, it is not sufficient to support their use in the clinical management. Our study suggests that lignans can be used as prospective agents for the treatment of neurodegenerative diseases and depression, with a view to informing their further development and utilization.

CD200R signaling contributes to unfavorable tumor microenvironment through regulating production of chemokines by tumor-associated myeloid cells.

CD200 is overexpressed in many solid tumors and considered as an immune checkpoint molecule dampening cancer immunity. In this study, we found that CD200R-/- mice were significantly more potent in rejecting these CD200+ tumors. scRNA sequencing demonstrated that tumors from CD200R-/- mice had more infiltration of CD4+ and CD8+ T cells, and NK cells but less infiltration of neutrophils. Antibody depletion experiments revealed that immune effector cells are crucial in inhibiting tumor growth in CD200R-/- mice. Mechanistically, we found that CD200R signaling regulates the expression of chemokines in tumor-associated myeloid cells (TAMCs). In the absence of CD200R, TAMCs increased expression of CCL24 and resulted in increased infiltration of eosinophils, which contributes to anti-tumor activity. Overall, we conclude that CD200R signaling contributes to unfavorable TME through chemokine-dependent recruitment of immune suppressive neutrophils and exclusion of anti-cancer immune effectors. Our study has implications in developing CD200-CD200R targeted immunotherapy of solid tumors.

Boosting the Methanol Oxidation Reaction Activity of Pt-Ru Clusters via Resonance Energy Transfer.

The sluggish kinetics of the methanol oxidation reaction (MOR) with PtRu electrocatalyst severely hinder the commercialization of direct methanol fuel cells (DMFCs). The electronic structure of Pt is of significant importance for its catalytic activity. Herein, it is reported that low-cost fluorescent carbon dots (CDs) can regulate the behavior of the D-band center of Pt in PtRu clusters through resonance energy transfer (RET), resulting in a significant increase in the catalytic activity of the catalyst participating in methanol electrooxidation. For the first time, the bifunction of RET is used to provide unique strategy for fabrication of PtRu electrocatalysts, not only tunes the electronic structure of metals, but also provides an important role in anchoring metal clusters. Density functional theory calculations further prove that charge transfer between CDs and Pt promotes the dehydrogenation of methanol on PtRu catalysts and reduces the free energy barrier of the reaction associated with the oxidation of CO* to CO2 . This helps to improve the catalytic activity of the systems participating in MOR. The performance of the best sample is 2.76 times higher than that of commercial PtRu/C (213.0 vs 76.99  mW cm - 2 mg Pt - 1 ${\rm{mW\ cm}}^{ - 2}{\rm{\ mg}}_{{\rm{Pt}}}^{ - 1}$ ). The fabricated system can be potentially used for the efficient fabrication of DMFCs.

Polysaccharide-Based Stimulus-Responsive Nanomedicines for Combination Cancer Immunotherapy.

Cancer immunotherapy is a promising antitumor approach, whereas nontherapeutic side effects, tumor microenvironment (TME) intricacy, and low tumor immunogenicity limit its therapeutic efficacy. In recent years, combination immunotherapy with other therapies has been proven to considerably increase antitumor efficacy. However, achieving codelivery of the drugs to the tumor site remains a major challenge. Stimulus-responsive nanodelivery systems show controlled drug delivery and precise drug release. Polysaccharides, a family of potential biomaterials, are widely used in the development of stimulus-responsive nanomedicines due to their unique physicochemical properties, biocompatibility, and modifiability. Here, the antitumor activity of polysaccharides and several combined immunotherapy strategies (e.g., immunotherapy combined with chemotherapy, photodynamic therapy, or photothermal therapy) are summarized. More importantly, the recent progress of polysaccharide-based stimulus-responsive nanomedicines for combination cancer immunotherapy is discussed, with the focus on construction of nanomedicine, targeted delivery, drug release, and enhanced antitumor effects. Finally, the limitations and application prospects of this new field are discussed.

Crystallization Regulation Engineering in the Carbon Nitride Nanoflower for Strong and Stable Electrochemiluminescence.

Cathode electrochemiluminescence (ECL) of C3N4 material has suffered from weak and unstable ECL emission for a long time, which greatly limits its practical application. Herein, a novel approach was developed to improve the ECL performance by regulating the crystallinity of the C3N4 nanoflower for the first time. The high-crystalline C3N4 nanoflower achieved a pretty strong ECL signal as well as excellent long-term stability compared to low-crystalline C3N4 when K2S2O8 was used as a co-reactant. Through the investigation, it is found that the enhanced ECL signal is attributed to the simultaneous inhibition of K2S2O8 catalytic reduction and enhancement of C3N4 reduction in the high-crystalline C3N4 nanoflower, which can provide more opportunities for SO4• - to react with electro-reduced C3N4• -, and a new "activity passivation ECL mechanism" was proposed, while the improvement of the stability is mainly ascribed to the long-range ordered atomic arrangements caused by structure stability in the high-crystalline C3N4 nanoflower. As a benefit from the excellent ECL emission and stability of high-crystalline C3N4, the C3N4 nanoflower/K2S2O8 system was employed as a Cu2+ detection sensing platform, which exhibited high sensitivity, excellent stability, and good selectivity with a wide linear range from 6 nM to 10 µM and a low detection limit of 1.8 nM.

A Unique, Porous C3N4 Nanotube for Electrochemiluminescence with High Emission Intensity and Long-Term Stability: The Role of Calcination Atmosphere.

Developing excellent strategies to optimize the electrochemiluminescence (ECL) performance of C3N4 materials remains a challenge due to the electrode passivation, causing weak and unstable light emission. A strategy of controlling the calcination atmosphere was proposed to improve the ECL performance of C3N4 nanotubes. Interestingly, we found that calcination atmosphere played a key role in specific surface area, pore-size and crystallinity of C3N4 nanotubes. The C3N4 nanotubes prepared in the Air atmosphere (C3N4 NT-Air) possess a larger specific surface area, smaller pore-size and better crystallinity, which is crucial to improve ECL properties. Therefore, more C3N4•- excitons could be produced on C3N4 NT-Air, reacting with the SO4•- during the electrochemical reaction, which can greatly increase the ECL signal. Furthermore, when C3N4 nanotube/K2S2O8 system is proposed as a sensing platform, it offers a high sensitivity, and good selectivity for the detection of Cu2+, with a wide linear range of 0.25 nM~1000 nM and a low detection limit of 0.08 nM.

A scaffold of thermally activated delayed fluorescent polymer dots towards aqueous electrochemiluminescence and biosensing applications.

To achieve the most efficient, all-exciton-harvesting organic electrochemiluminescence (ECL) for biosensing, aqueous thermally activated delayed fluorescence (TADF)-ECL (aqueous TADF-ECL) was successfully launched to provide a breakthrough for the theoretical ECL efficiency limitation of aqueous fluorescence ECL (aqueous FL-ECL). However, achieving efficient TADF emitters suitable for aqueous TADF-ECL remains challenging. A previous strategy relied on TADF small molecular nanoparticles (NPs). However, the aggregation caused quenching of such TADF molecules within NPs is intense, which renders such NPs inefficient for ECL emission. Herein, we propose developing conjugated polymer dots (Pdots) based aqueous TADF-ECL. Compared to the intrinsic TADF polymer, the Pdots achieve a comparable TADF photophysical properties in water, i.e., the comparable PL spectra, similar PL quantum efficiency (ΦPL) and intense delayed fluorescent contributions via a fast reverse intersystem crossing rate (kRISC) of 1.5 × 106 s-1. The resultant relative ECL efficiency (ΦECL) of the oxidative-reduction ECL system (C2O42- as the co-reactant) is as high as 11.73% (vs. the Ru(bpy)32+ counterpart). Additionally, satisfactory dopamine biosensing was accomplished for such TADF-Pdots/C2O42- couple. All those results are combined to highlight the promising potential of such an aqueous TADF-ECL strategy.

High-efficiency peroxidase mimics for fluorescence detection of H2O2 and L-cysteine.

Enzyme-based sensing platforms have undergone rapid development in the field of diagnosis and bioanalysis. Here we present a novel fluorescent artificial enzyme-based detection strategy for L-cysteine (Cys) and H2O2 by fabricating a series of Au-Ag bimetallic nanoparticles with peroxidase-like activity. Taking advantage of the enhanced performance of catalysts by optimizing the surface structure, the sensitive detection of Cys with an ultralow detection limit of 0.035 µM and accurate quantification in the range of 0.075-2 µM were achieved. It was revealed that the mechanism of the catalytic process on the Au-Ag surface follows the electron transfer mechanism rather than active species, that is the peroxidase-like catalysts work as electron transfer intermediates and the electron transfer efficiency will increase with the larger electron cloud density of active sites derived from the electronic synergistic effect between Au and Ag, contributing to the enhanced catalytic activity of peroxidase mimics. This finding could provide guidance for the structural design of high-activity peroxidase mimics.

Single-Molecule Nanocatalysis Reveals the Kinetics of the Synergistic Effect Based on Single-AuAg Bimetal Nanocatalysts.

Decades of extensive research efforts by scientists in the field of catalysis and nanomaterials have led to a large number of excellent bimetallic nanocatalysts. However, in many cases, the mechanism of the synergistic effect in bimetal catalyst-catalyzed reactions has been systematically neglected due to technical limitations. Herein, we use single-molecule fluorescence microscopy (SMFM) to reveal the mechanism of the synergy of the Au and Ag bimetal catalyst. Compared with that of the Ag nanocatalyst, the incorporation of Au changes the reaction pathway of Amplex Red and H2O2 from a noncompetitive to a competitive reaction mechanism, showing much higher catalytic efficiency. Additionally, the incorporation also inhibits the spontaneous surface reconstruction and facilitates the reaction-induced surface restructuring of the nanocatalyst, resulting in the enhancement of stability and reactivity. These findings provide useful insights into tailoring the reactivity of metal catalysts. This work also confirms the power of SMFM in revealing the origin of the catalytic activity of composite catalysts.

Unprecedented Dual Role of Polyaniline for Enhanced Pseudocapacitance of Cobalt-Iron Layered Double Hydroxide.

Creating nanosized pores in layered materials can increase the abundant active surface area and boost potential applications of energy storage devices. Herein, a unique synthetic strategy based on polyaniline (PANI) doped 2D cobalt-iron layered double hydroxide (CoFe-LDH/P) nanomaterials are designed, and the formation of pores at low temperature (80 °C) is developed. It is found that the optimized concentration of PANI creates the nanopores on the CoFe-LDH nanosheets among all other polymers. The well-ordered pores of CoFe-LDH/P allow the high accessibility of the redox-active sites and promote effective ion diffusion. The optimized CoFe-LDH/P2 cathode reveals a specific capacitance 1686 (1096 Cg-1 ) and 1200 Fg-1 (720 Cg-1 ) at 1 and 30 Ag-1 respectively, a high rate capability (71.2%), and a long cycle life (98% over 10 000 cycles) for supercapacitor applications. Charge storage analysis suggests that the CoFe-LDH/P2 electrode displays a capacitive-type storage mechanism (69% capacitive at 1 mV s-1 ). Moreover, an asymmetric aqueous supercapacitor (CoFe-LDH/P2//AC) is fabricated, delivering excellent energy density (75.9 Wh kg-1 at 1124 W kg-1 ) with outstanding stability (97.5%) over 10 000 cycles. This work opens a new avenue for designing porous 2D materials at low temperature for aqueous energy storage devices.

Graphene oxide-assisted synthesis of N, S Co-doped carbon quantum dots for fluorescence detection of multiple heavy metal ions.

Detection of heavy metal ions (HMIs) in water is an important topic in the field of analytical chemistry and environmental science. Fluorescence spectroscopy is one of the most promising strategies due to its simple instrument, low investment, rapid and convenient operation. However, current fluorescence probes for detecting HMIs are typically selective for certain ions. Herein we reported the development of a novel strategy that determined the total content of HMIs in water by fluorescence spectroscopy. A novel fluorescent nitrogen, sulfur co-doped carbon quantum dots (N, S-CQDs) was prepared via graphene oxide-assisted synthesis method. The results showed that, with the fluorescence quenching strategy, N, S-CQDs exhibited a wide linear response to a series of water-soluble metal ions. The fluorescence of N, S-CQDs is stable in a wide range of pH 4-11. The detection mechanism was proved that the integration, caused by coordination interaction between S element in N, S-CQDs and the d-orbital of associated metal ions, was the main reason for fluorescence quenching. In practice, the N, S-CQDs were applied to determine total content of HMIs in water successfully. Interestingly, further experiment proved that the N, S-CQDs could effectively remove HMIs in water after centrifuging and filtering thoroughly. It was shown that the fluorescence of N, S-CQDs was obviously quenched by the multiple-ions-involved water and scavenging effect of N, S-CQDs on HMIs with centrifugal in which the concentration of individuals meets the Chinese National Standard. This indicates that the N, S-CQDs are of a wide application prospect in water quality analysis.

Binder-free Fe-doped NiCo2O4/Ni3S4 hollow heterostructure nanotubes for highly efficient overall water splitting.

For overall water splitting, a vital challenge is to design active sites at interfaces. Heterogeneous catalysts with enhanced mass/charge transfer and accelerated adsorption of intermediates have exhibited significantly enhanced activities. Herein, a Fe-doped NiCo2O4/Ni3S4 heterogeneous electrocatalyst is synthesized for the HER and OER. On account of the synergistic effect of heterostructures, Ni-O-S presents a low overpotential of 29.1 mV (10 mA cm-2), a relatively small Tafel slope of 53.3 mV dec-1 for the HER, and 259 mV at a current density of 100 mA cm-2 (33.1 mV dec-1) for the OER. What is more, Ni-O-S acts as a binder-free bi-functional electrode in an alkaline electrolyte for overall water splitting, exhibiting a cell voltage of 1.45 V (10 mA cm-2) with good stability. This work offers an efficient approach for designing stable and high-efficiency heterogeneous electrodes for overall water splitting.

Aggregation-induced delayed fluorescence luminogens: the innovation of purely organic emitters for aqueous electrochemiluminescence.

Due to overcoming the limitation of aggregation caused quenching (ACQ) of solid-state emitters, aggregation-induced emission (AIE) organic luminogens have become a promising candidate in aqueous electrochemiluminescence (ECL). However, restricted by the physical nature of fluorescence, current organic AIE luminogen-based ECL (AIECL) faces the bottleneck of low ECL efficiency. Here, we propose to construct de novo aqueous ECL based on aggregation-induced delayed fluorescence (AIDF) luminogens, called AIDF-ECL. Compared with the previous organic AIE luminogens, purely organic AIDF luminogens integrate the superiorities of both AIE and the utilization of dark triplets via thermal-activated spin up-conversion properties, thereby possessing the capability of close-to-unity exciton utilization for ECL. The results show that the ECL characteristics using AIDF luminogens are directly related to their AIDF properties. Compared with an AIECL control sample based on a tetraphenylethylene AIE moiety, the ECL efficiency of our AIDF-ECL model system is improved by 5.4 times, confirming the excellent effectiveness of this innovative strategy.

Graphite-like Carbon Nitride Nanotube for Electrochemiluminescence Featuring High Efficiency, High Stability, and Ultrasensitive Ion Detection Capability.

Herein, for the first time, we introduced a novel electrochemiluminescence (ECL) luminophore based on a one-dimensional g-C3N4 nanotube using K2S2O8 as the coreactant. The g-C3N4 nanotube/K2S2O8 couple displayed very satisfactory ECL performance, i.e., an ECL efficiency (ΦECL) of 437% (vs 100% for the Ru(bpy)32+/K2S2O8 reference) and excellent ECL stability (the relative standard deviation (RSD) = 0.78%). By contrast, ΦECL and RSD of the control g-C3N4 nanosheet/K2S2O8 couple were merely 196% and 45.34%, respectively. The mechanism study revealed that the g-C3N4 nanotube features a large surface area and much lower interfacial impedance in the porous microstructure, which are beneficial for accelerating the charge transfer rate and stabilizing charge/excitons for ECL. Moreover, using the g-C3N4 nanotube/K2S2O8 system as a sensing platform, excellent Cu2+ detection capability was also achieved. Our work thus triggers a promising g-C3N4 nanomaterial system toward ECL application.